Flat panel displays have been produced by using many vacuum processing apparatus such as sputtering apparatus for forming metal wiring films, each having a vacuum chamber.
To improve the yield in production of flat panel displays, the glass substrate forming display continues to be increased in size. With the jumboization of this glass substrate, the chamber itself in the processing apparatus is being increased in size such that film formation process and the like can be performed over the entire surface of the substrate. For example, if a glass substrate having a size of 2,850 mm×3,050 mm is to be processed, the processing chamber may have its height or width exceeding 5 m. If such an assembled chamber is to be transported to a desired installation site, a large-scaled transportation means such as large-sized trailer is required.
Since such a large-sized chamber formed from flat, it is also required to provide reinforcing members on the discrete outer walls of the chamber to maintain the necessary intensity thereof. Each of the reinforcing members is attached to the corresponding surface of the chamber mainly by welding. However, the whole chamber may be further increased in size by the attachment of the reinforcing members. This raises a problem in that the chamber will not be able to be transported under legal restrictions relating to size and weight.
To overcome such a problem, a chamber having side walls which are formed by welding a plurality of wall components together has been proposed (e.g., refer to a patent document 1). If the discrete wall components are transported to an installation site and then welded together therein, a large-sized chamber can be relatively easily transported to and assembled in the installation site.
Patent Document 1:
    Japanese Laid-Open Patent Publication Hei 8-64542 (FIG. 1)